While I agree that it may be a good idea with certain groups (age/skill can be a factor), I also agree with John that knowing how to use a razor knife is an important skill to learn if the student wants to excel as most any hobby or craft.
In my beginner and advanced classes I introduce knife work by the 2nd session of the beginner classes and it is expected that you know how to use a knife if you move up to the advanced classes.
To eliminate knives in class you can either select models that don't require a knife to assemble or kits that require a minimum of such use. Our Thing-a-ma-Jig is a good example. The only knife use is to cut the slit in the motor tube for the hook. When asked about this I tell the teacher that they can cut these slits themselves before class, while the tube is in the bag (just cut through the bag).
As for safe knife use I give the kids what has become known as my standard "knife lecture". If there are others in the room who have already heard it, they always groan, but suffer through the lecture again
I provide all of the standard information and demonstrations on how to use a knife. Use a cutting board, draw the knife towards you, do not use too much pressure, hold knife as you would a pencil, not a baseball bat, keep your knife hand in contact with the work surface at all times, use a straight edge when appropriate, turn the work being cut, not the knife, etc.
In addition to all the (what I call standard) how-to and safety, I go a bit further with this:
- I SHOW them how sharp the knives are (cutting a sheet of paper held up with little/no support)
- I describe times I have cut myself and what I was doing wrong
- I describe times other students have cut themselves, and what they were doing wrong
- I explain that I have zero tolerance for goofing off with a knife (see below)
Goofing off with the knife (and being distracted) are the biggest problems I have seen in knife use. If you've taught kids, you've all see them looking through the body tube like a telescope, or waving it around like a bat, etc. This is distracting, but not dangerous in itself.
However, with knives it is unacceptable. I forewarn them that if they use the knife for ANYthing other than what it is designed for (in this case, cutting fins), they will loose it for the entire session and they will be unable to build their rocket. I further explain that this is not *my* problem but their problem and they are more than invited to explain to their parents how they were goofing off with the knife if they wish (only happened once and the other kids got to see the result
)
once they realize I am serious they pay far more attention. It has helped that several students have seen me take a knife from a student so they know I will do it if needed.
My experience is that once they take knife use seriously and realize it can be dangerous if you're not careful they tend to be very careful and conscious of what they are doing.
Hope this helps!
jim